Potassium Carbonate → ethyl 8-carbamoyl-5-(2,6-difluorophenyl)-2,3,4,9-tetrahydro-1H-carbazole-2-carboxylate

HRID 661906Notes

Reaction equation

HRID 661906 reaction equation
Br[C:2]1[CH:14]=[CH:13][C:12]([C:15](=[O:17])[NH2:16])=[C:11]2[C:3]=1[C:4]1[CH2:5][CH2:6][CH:7]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[CH2:8][C:9]=1[NH:10]2.[F:23][C:24]1[CH:29]=[CH:28][CH:27]=[C:26]([F:30])[C:25]=1B(O)O.C1(P(C2CCCCC2)C2C=CC=CC=2C2C(OC)=CC=CC=2OC)CCCCC1.C(=O)([O-])[O-].[K+].[K+]>C1COCC1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd]>[C:15]([C:12]1[CH:13]=[CH:14][C:2]([C:25]2[C:24]([F:23])=[CH:29][CH:28]=[CH:27][C:26]=2[F:30])=[C:3]2[C:11]=1[NH:10][C:9]1[CH2:8][CH:7]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[CH2:6][CH2:5][C:4]2=1)(=[O:17])[NH2:16]

Participants

7

Reactant 4

HCID 11430Potassium CarbonateHCID 27343362,6-Difluorophenylboronic acidHCID 112698722-Dicyclohexylphosphino-2',6'-dimethoxybiphenylHCID 59375013ethyl 5-bromo-8-carbamoyl-2,3,4,9-tetrahydro-1H-carbazole-2-carboxylate2×

Product 1

HCID 46834100ethyl 8-carbamoyl-5-(2,6-difluorophenyl)-2,3,4,9-tetrahydro-1H-carbazole-2-carboxylateYield 45.6%

Reagents, catalysts & solvents 2

HCID 9811564Bis(dibenzylideneacetone)palladiumCatalystHCID 8028TetrahydrofuranSolvent

Procedure

A mixture of ethyl 5-bromo-8-carbamoyl-2,3,4,9-tetrahydro-1H-carbazole-2-carboxylate (Intermediate 47-1, 20 mg, 0.055 mmol), 2,6-difluorophenylboronic acid (17.3 mg, 0.110 mmol), dicyclohexyl(2′,6′-dimethoxybiphenyl-2-yl)phosphine (4.5 mg, 11.0 mmol), potassium carbonate (15.1 mg, 0.110 mmol) and tris(dibenzylideneacetone)dipalladium (5.0 mg, 0.005 mmol) in THF (2 mL) was purged with nitrogen for 2 min, then was heated in a sealed tube overnight. The mixture was filtered and concentrated, and the residue was purified by preparative HPLC. The appropriate effluent fractions were made basic with 1 M aqueous sodium hydroxide and extracted twice with DCM. The combined organic phases were washed with water, dried and concentrated to provide ethyl 8-carbamoyl-5-(2,6-difluorophenyl)-2,3,4,9-tetrahydro-1H-carbazole-2-carboxylate as a light yellow solid (10 mg, 44%). 1H NMR (400 MHz, chloroform-d) δ 10.10 (1H, br. s.), 7.31-7.44 (2H, m), 6.95-7.06 (3H, m), 4.10-4.22 (2H, m), 2.96-3.12 (2H, m), 2.80 (1H, dddd, J=17.52, 5.99, 3.08, 2.86 Hz), 2.27-2.41 (1H, m), 2.15-2.27 (1H, m), 2.04-2.14 (1H, m), 1.69-1.85 (1H, m), 1.26 (3H, t, J=7.25 Hz). Mass spectrum m/z 399.1 (M+H)+.

Workup

  1. customwas purged with nitrogen for 2 min
  2. temperaturewas heated in a sealed tube overnight
  3. filtrationThe mixture was filtered
  4. concentrationconcentrated
  5. customthe residue was purified by preparative HPLC
  6. extractionextracted twice with DCM
  7. washThe combined organic phases were washed with water
  8. customdried
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-eed51b2f7f25476d98e6579317f9c2a1
Source dataset
uspto-grants-2011_12
Patent number
US08084620B2

Reaction notes

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